STATEN ISLAND, N.Y. -- A trip along Upper New York Bay was anything but routine Thursday afternoon, as passengers aboard the Staten Island Ferry encountered a moment of horror when the vessel slammed against the Whitehall pilings.

According to riders aboard the 2 p.m. Guy V. Molinari boat, the ferry heading to Staten Island suddenly slowed by the Statue of Liberty and then reversed course to Whitehall Ferry Terminal because of mechanical and power issues announced by the crew.

As they reached Whitehall, the crew advised passengers to brace for impact and get on the ground. The boat was unable to fully stop, resulting in a hard landing.

Alissa Flockerzi, U.S. Coast Guard Public Affairs Specialist Third Class, said the ferryboat appeared to have suffered a "mechanical failure" after leaving Whitehall.

"They tried pulling back into the port, and that's why they struck it," she said Thursday afternoon. "We do actually have a Coast Guard investigator on the scene now."

We were almost halfway to SI and the ferry headed back to Manhattan. Had to lay on the ground as we docked because of the impact.

The Department of Transportation reported no injuries or damage to the boat, but minimal damage to the pedestrian bridge that links the ferryboat to the terminal.

"The vessel experienced a mechanical issue on departure and returned to Whitehall, where it came against the pilings and the lower level [pedestrian] bridge at low speed," said DOT spokesman Nicholas Mosquera. "There were no reported injuries thanks to the crew who advised passengers to brace on landing."

Mosquera said Thursday evening the crew is investigating the mechanical issue but there are no further details at this time.

"The ferry immediately returned to regularly scheduled service, though it will be on three-boat schedule for the [Thursday] evening rush before returning to full service," the spokesman said.

One passenger didn't realize there was a problem until he glanced from his laptop and saw the Statue of Liberty closer than usual.

"Great view, I thought," said Bernardo Pace, 59, an English professor at the Borough of Manhattan Community College who lives in West Brighton.

He said he then noticed the Verrazano-Narrows Bridge to his left. He wondered if the boat went rogue. "I got up and pointed out to my neighbors where we were, and everyone agreed the boat never went so close to the Statue of Liberty."

After the incident, he and other passengers boarded the next ferry at 2:30 p.m. from Whitehall, the John F. Kennedy.

About 45 minutes after the accident, about half a dozen fire trucks were still gathered at Whitehall Terminal, though they weren't very busy. A firefighter in a wetsuit had clearly not needed to use it, and passengers waiting for the 3:30 p.m. boat were unfazed and seemingly unaware there had been an incident.

The ferryboat Molinari sat in Slip 1, and crew members could be seen moving about in the crow's nest of the boat. But that was the only sign of movement on the ship, and from the terminal, there was no visible damage.

Meanwhile, across the pond, at the St. George Ferry Terminal, passengers waiting for the boat about an hour later had no idea what had happened at Whitehall, and operations there continued as normal.

Moments after the incident, riders took to Twitter to voice their concerns and share their experiences.

"Staten Island ferry speakers just said brace for impact then crashed into the dock #wild," said a user identifying himself as Ryan Schanz (@FreedomWilknson).

A St. George resident aboard the ship said the crew handled the situation very well. The woman, who only gave her first name, Sally, said "It was scary for a second when they told us to get on the ground. After we hit, it was fine."

Randall Manor resident Bob Olivari was also on the Molinari at the time of the incident.

"My question is this: Why is it after all this time, the most dependable boat is the Kennedy? And [that's the] only one boat in service from that whole class," he said, adding that tens of millions of dollars have been spent on the newer fleet of boats. "And they don't work."

Olivari said he hopes the new mayor pays attention to this ongoing problem, "because it's only going to get worse." 